Resize an iframe to fit its content

This snippet gets the height of an iframe’s content and then sets the height of the iframe to match.

Assume that frame represents the iframe element.

frame.addEventListener('load', function() {
    // Get the height of the content
    const height = frame.contentDocument.body.scrollHeight;

    // Set the height of iframe
    frame.setAttribute('height', `${height}px`);
});

Source

https://htmldom.dev/resize-an-iframe-to-fit-its-content/